The City of Thieves

{t} Add {w},{u},{b},{r},or {g}
Creatures you control have Gamble (When this creature attacks you may flip a coin,
if heads put a +1/+1 counter on it, if tails put a -1/-1 counter on it)
Whenever a Thief comes into play you gain 2 life, or target player loses 2 life.
{4}: Create a 2/2 Thief token
{2}: Create a 1/1 Mouse token with lifelink